1 tablespoon olive oil
1 1/2 cups chopped yellow onion
1/2 cup sweet red vermouth (such as Martini Rossi), divided
2 tablespoons Dijon mustard
1 tablespoon whole-grain mustard
2 teaspoons lightly chopped fresh thyme
In a medium saucepan over medium-high heat, combine the chicken stock and mushrooms. Bring to a simmer and cook for 5 minutes. Remove from the heat, cover and set aside.
Refrigerate the mushrooms and chicken stock overnight. The next day, remove and discard the mushroom stems. Cut mushroom caps in half and return to the stock.
Heat the oven to 325 degrees. Season all the chicken pieces with salt and pepper.
In a large Dutch oven or other oven-safe pot, heat the oil over medium-high. Add the chicken, half at a time if necessary, and brown on both sides, 3 to 4 minutes per side. Transfer the chicken to a plate, then add the onions to the pan. Cook over medium heat until the onions are softened, about 3 minutes. Add half of the vermouth and stir to deglaze the pan.
Return the chicken to the pan, then add the stock and mushroom mixture. Cover and bring to a simmer.
Transfer the pot to the oven and bake, covered, for 30 to 35 minutes, or until the chicken is cooked through.
Once the chicken is cooked, uncover the pot. Place the pot on a burner over medium heat and add both mustards, the remaining vermouth and the thyme. Bring to a simmer and cook, uncovered, for about 10 minutes, or until the sauce thickens slightly and glazes the chicken.
Divide the chicken among 4 plates. Spoon the sauce over and around the chicken.
• Rocco DiSpirito is author of the “Now Eat This!” and “Now Eat This! Diet” cookbooks.